brew/Library/Homebrew/debrew/irb.rb

require "irb"

module IRB
  @setup_done = false

  extend Module.new {
    def parse_opts; end

    def start_within(binding)
      unless @setup_done
        setup(nil)
        @setup_done = true
      end

      workspace = WorkSpace.new(binding)
      irb = Irb.new(workspace)

      @CONF[:IRB_RC]&.call(irb.context)
      @CONF[:MAIN_CONTEXT] = irb.context

      trap("SIGINT") do
        irb.signal_handle
      end

      begin
        catch(:IRB_EXIT) do
          irb.eval_input
        end
      ensure
        irb_at_exit
      end
    end
  }
end